The ultrasonic-assisted extraction of polyphenols from peanut skins was optimized using response surface methodology. The extraction yield of polyphenols was investigated with respect to four process parameters including ultrasonic treatment time, ultrasonic power, ethanol concentration and solid-to-solvent ratio. As a result, a quadratic polynomial mathematical model was built. In theory, the optimal extraction conditions were determined as follows: peanut skins were suspended in 51% ethanol aqueous solution at a solid-to-solvent ratio of 1:29.6 (g/mL) and then subjected to ultrasonic treatment for 24.4 min at a power of 408 W. For practical applications, the same extraction solvent was used, but the solid-to-solvent ratio, ultrasonic treatment time and power were modified to be 1:30 (g/mL), 24 min and 410 W, respectively. Under the modified conditions, the extraction yield of polyphenols was 8.95%.

The production of instant high dietary fiber cornflake form whole corn flour and corn dietary fiber by twin-screw extrusion was optimized using response surface methodology. The overall quality score of final products was investigated with respect to the amounts of water and corn dietary fiber added to whole corn flour and corn dietary fiber particle size. A second-order regression model was constructed using a three-variable, three-level central composite design and the optimum process parameters were determined by response surface analysis. Addition of 52% water and 29% corn dietary fiber with a particle size of 120 mesh (0.125 mm) provided the best quality of final products.

This study deals with the optimization of homogenization conditions for the extraction of proanthocyanidin from Ginkgo biloba leaves using response surface methodology. The effects of extraction solvent, solid-to-solvent ratio, and homogenization speed and time on the extraction yield of proanthocyanidin was investigated by one-factor-at-a-time method. Further investigations were carried out to optimize the process parameters through response surface analysis of a mathematical model for the extraction yield of proanthocyanidin as their function built based on a Box-Behnken experimental design. The optimal conditions for extracting proanthocyanidin from Ginkgo biloba leaves were found to be homogenization at a rotary speed of 10500 r/min for 5.87 min with an absolute ethanol-to-Ginkgo biloba leaves of 1:23.8 (g/mL). Under these conditions, the extraction yield of proanthocyanidin was 2.21%.

A central composite design (CCD) was used to optimize the ultrasonic-assisted extraction of total xanthones from mangosteen pericarp. The effects of ethanol concentration, ultrasonication time and solvent-to-solid ratio as well as their interactions on the extraction rate of total xanthones were investigated. A predictive regression model was developed using the SAS software by response surface analysis and its reliability was validated. The optimal extraction conditions were 90.9% of ethanol concentration, 17.1:1 (mL/g) of solvent-to-solid ratio and 73.8 min of ultrasonication time as determined by ridge analysis, resulting in an average actual yield of total xanthones of 7.73% (n = 3).

This work reports the use of response surface methodology to optimize conditions for the extraction of arachin and conarachin from defatted soybean meal. Defatted soybean meal was suspended in 0.03 mol/L Tris-HCl buffer at a constant temperature and stirred for 1 h. As a result, arachin and conarachin were extracted into the supernatant. Temperature, pH and solvent/solid ratio were tested for their effects on the solubility of arachin and conarachin. The best solubility of arachin and conarachin was observed when the extraction conditions were 62.93 ℃, pH 9.04 and 15.11:1 (mL/g). In addition, the experimental NSI values of arachin and conarachin were 54.82% and 74.1%, respectively, which were close to the predictive values. Accordingly, response surface methodology can be a reasonable and feasible approach to optimizing conditions for the extraction of peanut proteins.

In the present study, three aqueous extraction techniques, water bath extraction, direct heating extraction and microwave-assisted extraction were compared to determine the most suitable one for maximum extraction yield of water-soluble flavonoids from Angelica keiskei Koidzumi leaves. The water bath extraction method provided maximum extraction of water-soluble flavonoids and the optimal extraction conditions were heating at 95 ℃ for 10 min. Further investigations were carried to explore the purification of the resulting crude extract under various conditions of macroporous resin type, sample loading amount, and elution solvent (ethanol) pH, ethanol concentration and elution volume. HP-20 type resin was found to have higher adsorption and desorption capacities for flavonoids and the optimal conditions for purifying water-soluble flavonoids from Angelica keiskei Koidzumi leaves using the resin were determined as follows: 40 mL of crude extract sample at 2.445 mg/mL were loaded onto HP-20 type resin and then desorbed with 8 BV of 70% acidified ethanol (pH 2), resulting in a purification factor of approximately 6.8.

In order to find optimal conditions for the malting of naked oats, the effects of steeping temperature (11–19 ℃), germination temperature (11–19 ℃) and germination time (2–6 d) on β-glucan and phytic acid contents and protein digestibility in vitro of oat malts were studied by one-factor-at-a-time and orthogonal array design methods. β-glucan and phytic acid contents and protein digestibility in vitro were not substantially affected by steeping temperature. β-glucan and phytic acid contents decreased with increasing germination temperature and germination time. Protein digestibility in vitro increased with prolonged germination time but was only minorly affected by germination temperature. The optimal conditions for the malting of naked oats were determined as follows: the steeping procedure was performed at 14 ℃ and followed a pattern of steeping for 6 h, relaxation for 10 h, steeping for 4 h, relaxation for 7 h, steeping for 3 h, and relaxation for 1 h before germination at 15 ℃ for 4 d. Under these conditions, oat malts revealed a 42.8% decrease in phytic acid content and a 142.1% increase in protein digestibility in vitro. Therefore, the nutritional quality was improved.

The production of xylo-oligosaccharides (XOS) from corncobs was performed by steam explosion pre-treatment combined with selectively enzymatic hydrolysis with endo-xylanase. A new precise quantification method for XOS with a degree of polymerization (DP) of 2–6 was developed using high performance anion-exchange chromatography coupled with pulsed amperometric detector (HPAEC-PAD). The effects of pretreatment intensity and major parameters (reaction temperature and reaction time) on the composition distribution and yield of XOS were investigated in order to find optimal steam explosion pretreatment conditions. The results indicated that the optimal explosion intensity factor, temperature and holding time for steam explosion pretreatment of corncobs were 3.76, 200 ℃ and 390 s, respectively. Under these conditions, the highest yield of XOS was 20.8%. The resulting product was mainly composed of xylotriose, xylotetraose and xylobiose with a relative content of 43.5%, 21.3% and 18.6%, respectively.

The aqueous enzymatic extraction of polysaccharides from rapeseed meal was optimized by response surface methodology. One-factor-at-a-time method was employed to investigate the effects of five operating parameters on polysaccharide yield. The optimum ratio of water to material was 25:1 (mL/g). Further, a quadratic polynomial regression model describing polysaccharide yield as a function of enzyme dosage, pH, temperature and extraction time was developed using the SAS software based on a Box-Behnken experimental design. The results of response surface analysis showed that the optimal extraction conditions were extraction at 62 ℃ and pH 6.7 for 79 min with an enzyme dosage of 256 U/g, resulting in a polysaccharide yield as high as 9.01%.

The extraction of flavonoids from Gynura crepidioides stems and leaves was optimized using an L9(34) orthogonal array design. The effects of ethanol concentration, temperature, extraction time and solid/solvent ratio on extraction efficiency were examined. The optimal extraction conditions were found to be extraction at 65 ℃ for 3.5 h with 70% ethanol with a solid/solvent ratio of 1:30 (g/mL). Under these conditions the measured extraction yield of flavonoids from Gynura crepidioides stems and leaves was 31.88 mg/g. The obtained extract had a considerable scavenging effect against hydroxyl free radicals in a dose-dependent fashion. Besides, it also could scavenge superoxide anion free radicals. Based on these results, it can be concluded that flavonoids from Gynura crepidioides stems and leaves have the potential to be developed as promising free radical scavengers.

Response surface methodology was used to optimize conditions for the microwave-assisted extraction of flavonoids from Perilla frutescens leaves. The effects of raw material particle size, extraction time, temperature, ethanol concentration and solid-to-solvent ratio on extraction efficiency were investigated. The optimal conditions for extracting flavonoids from Perilla frutescens leaves were found to be extraction at 71 ℃ for 70 min with 61% ethanol at a solid-to-solvent ratio of 1:20 (g/mL) and a raw material particle size of 20 mesh. Under these conditions, the maximum extraction yield of flavonoids was 59.28 mg/g. The obtained extract was purified by D152 macroporous resin column chromatography and the purified product mainly consisted of lutin and luteolin as demonstrated by UV absorption spectrometry and HPLC.

In order to increase the drying efficiency of heat pump-microwave drying for tilapia fillets and the quality of dried tilapia fillets, the effects of heat pump temperature and airflow rate and microwave drying time and power on the rate of moisture reduction, rehydration rate and sensory quality of tilapia fillets were investigated. Meanwhile, the appropriate moisture content at the transition from heat pump to microwave was explored. The results indicated that during the heat pump drying stage low-temperature (35 ℃) drying was necessary to prevent severe protein denaturation, nutrient loss, yellowing and texture hardening of tilapia fillets; in addition, an airflow rate of 3.0 m/s was adopted to prevent hard shell effect. During the microwave drying stage, intermittent drying for 1 min at 1-min intervals was used to improve the taste of tilapia fillets, maintain better color and attenuate protein denaturation. The drying rate became slower when the moisture content was reduced to 40% during the heat pump drying process suggesting the moisture content at the transition from heat pump to microwave to be 40%.

This paper reports the application of orthogonal array design method to optimize the successive extraction of saponins, flavonoids and polysaccharides from Gynostemma pentaphyllum stems and leaves. The solvents used for the extraction of the phytochemicals were aqueous ethanol solutions at decreasing concentrations. The optimal ethanol concentration for saponins flavonoids and polysaccharides was 80%, 30% and 5%, respectively, resulting in an extraction efficiency of 8.75%, 0.75% and 3.38%, respectively. The successive extraction procedure showed more efficient utilization of raw materials than single extraction procedures and therefore could provide references for the comprehensive utilization of Gynostemma pentaphyllum.

This study was undertaken to optimize reaction conditions for the biocatalytic deacylation of phosphatidylcholine (PC) by lipase to glycerol-3-phosphocholine (GPC) in non-aqueous phase. The optimal reaction conditions were found to be reaction at 40 ℃ and pH 5.0 for 6 h with an enzyme dose of 12.5 mg/mL in the presence of 4% water. Moreover, in order to increase the utilization rate of lipase and reduce solvent consumption, additional PC at a concentration of 0.437 g/mL was added in a proportion of 50% relative to the initial amount after 1.5 h during the reaction process. Under these process conditions, the average yield of GPC after aqueous extraction of reaction products was 97% (n = 3) as determined by HPLC.   Thus, a feasible method to prepare GPC has been established.

The effects of solid-to-liquid ratio, enzyme loading, temperature and hydrolysis time on the efficacy of cellulase for cell wall disruption of rape bee pollen were examined in this study. One-factor-at-a-time and orthogonal array design methods were used to optimize the experimental conditions based on cell wall disruption rate and polysaccharide yield. The optimal conditions for cell wall disruption of rape bee pollen were found to be hydrolysis at 47.5 ℃ for 5.0 h with a solid-to-liquid ratio of 1:50 (g/mL) and an enzyme loading of 1.75%, resulting in a cell wall disruption rate of 85.72% and a polysaccharide yield of 18.85%.

The ultrasonic-assisted surfactant extraction of total flavonoids from bamboo leaves was optimized by one-factor-at-a-time method and response surface methodology. The extraction yield of total flavonoids was investigated with respect to ultrasound power, surfactant type, surfactant critical micelle (CMC) concentration and solvent-to-solid ratio. The results showed that the optimal conditions for the extraction of total flavonoids at 40 kHz ultrasonic power and ambient temperature were ultrasound power of 420 W, SDS as the extraction surface at a CMC of 25.20×10-3 mol/L, and a solvent-to-solid ratio of 23:1 (mL/g) (ratio of SDS solution to bamboo leaves). Under these conditions, the yield of total flavonoids was 2.30%.

Serious emulsification occurring during aqueous phase extraction of oil leads to low oil yield. In the present study, we used response surface methodology to optimize the extraction of camellia seed oil for the purpose of maximizing oil yield. A mathematical model that describes oil yield as a function of solvent-to-solid ratio, temperature and extraction time was fitted. The optimal extraction conditions were found to be extraction at 61.56 ℃ for 1.26 h with a solvent-to-solid ratio of 3.13:1 (mL/g). Under the optimal conditions, the predicted oil yield was 98.02%. The results of validation experiments suggested these extraction conditions to be reliable.

The extraction of water-soluble polysaccharides from immature fruits of Schisandra chinensis (Turcz.) Baill was optimized by one-factor-at-a-time and orthogonal array design methods. Crude polysaccharides were separated from the resulting extract by means of ethanol precipitation and deproteinized by Sevag method. The antioxidant activity of crude and purified polysaccharides was investigated and compared with that of VC. The optimum extraction conditions were found to be three cycles of extraction at 90 ℃ for 2 h with a solid-to-liquid ratio of 1:30 (g/mL). Purified polysaccharides contained nearly no protein or nucleic acid as demonstrated by UV spectroscopic analysis and had common spectral characteristics of polysaccharides as showed by infrared spectroscopic analysis. Both polysaccharide samples had scavenging effects against hydroxyl and superoxide anion free radicals and the free radical scavenging effect of deproteinized polysaccharides was stronger. The corresponding IC50 values against superoxide anion and hydroxyl free radicals were 66.03 mg/mL and 6.49 mg/mL, respectively, suggesting purified polysaccharides to be a strong scavenger against hydroxyl free radicals. Crude and deproteinized polysaccharides, however, had weaker antioxidant activity than VC.

In this study, different solvents were compared for their effectiveness in extracting pigments from flower petals of Gentiana rhodantha Franch. ex Hemsl.. Seventy percent ethanol was found to be the best solvent for the extraction of pigments. The crude pigment extract had maximum absorption at 531 nm and showed a poor tolerance to UV, high temperature, VC, hydrogen peroxide and sodium sulfite. It was not almost affected by glucose, sucrose and citric acid and only slightly affected by Na+, Ca2+ and A13+, but Fe2+ caused a noticeable hyperchromic effect. The red color of the pigments was maintained at pH levels equal to or less than 3 but completely damaged in neutral or alkaline environments. Based on these results, we speculated that the pigments belong to the class of anthocyanins which contains phenolic hydroxyl groups.

Barley malt roots as a byproduct of malt product was analyzed for proximate chemical composition according to the national standards. Meanwhile, the extraction of alkali-soluble protein from barley malt roots was optimized by orthogonal array design method. Barley malt roots contained 29.2% protein, 6.9% ash, 6.42% water, 1.4% fat and 10.7% crude fiber. The optimal conditions for protein extraction were found to be extraction at 40 ℃ and pH 9.0 for 60 min with a solid-to-solvent ratio of 1:25 (g/mL), resulting in a protein yield of 63.5%. The optimized procedure provided a simple and high-yield method for protein extraction from barley malt roots.

The present study was conducted to determine optimal conditions for the purification of salicin from the dried roots of Alangium chinense (Lour.) by macroporous resin adsorption. Among 8 types of macroporous resins, HPD-826 was found to be the best one for the adsorption and desorption of salicin. Adsorption and desorption conditions were optimized for the application of HPD-826 to purify salicin from crude extract from the dried roots of Alangium chinense (Lour.). The best purification results were obtained when 6.5 BV of crude extract sample at a concentration 45.12 μg/mL was loaded onto an HPD-826 column with a diameter/height ratio of 1:8 at a flow rate of 3 BV/h and afterwards, the column was washed with 4 BV of deionized water for the removal of water-soluble impurities and eluted with 5 BV of 30% ethanol. The resulting recovery of salicin was approximately 78%. In conclusion, HPD-826 had a good overall performance for purifying salicin, and the proposed procedure was stable and feasible and therefore suitable for industrial applications.

A high-yield method for the extraction of polysaccharides from Sargassum pallidum was proposed using an integrated ultrasonic and microwave reaction system. The extraction yield of polysaccharide was measured by phenol-sulferic acid method. The optimal conditions of raw material particle size, extraction time, solid-to-solvent ratio, ultrasonic power and microwave power for extracting polysaccharides from Sargassum pallidum were 40 mesh, 20 min, 1:25 (g/mL), 75% and 200 W, respectively, as determined by orthogonal array design. Among five operating parameters, raw material particle size was the most important factor for polysaccharide extraction. The combined use of ultrasonic and microwave provided a time-saving and high-yield method for polysaccharide extraction from Sargassum pallidum.

Ethanol reflux extraction was selected for the extraction of total flavonoids from Fructus Polygoni Orientalis due to its advantages such as high yield, simplicity and low cost over other three extraction techniques, Soxhlet extraction, ultrasonic-assisted extraction and aqueous extraction. In order to achieve maximum extraction efficiency, the ethanol reflux extraction process was optimized using an orthogonal array design. The optimal extraction conditions were determined as two extraction cycle with 55% ethanol at a solid-to-solvent ratio of 1:24 (g/mL) and 90 ℃ for 4 h. Under these conditions, the extraction yield of total flavonoids was 7.06%.

The current study was carried out to optimize the ultrasonic-microwave assisted extraction of chlorogenic acid from Flos Lonicerae. The extraction yield of chlorogenic acid was investigated with respect to temperature, ethanol concentration, solid-to-solvent ratio, microwave power and irradiation time. The combined use of ultrasonic and microwave provided higher extraction efficiency than their individuals. An extraction yield of chlorogenic acid of 5.93% was obtained when ultrasonication for 30 min followed by microwave irradiation at a power of 400 W for 5 min was used for the extraction of Flos Lonicerae with 70% ethanol at a solid-to-solvent ratio of 1:15 (g/mL).

Response surface methodology was used to optimize conditions for the supercritical fluid extraction with carbon dioxide of β-carotene from watermelon bee pollen, and crude β-carotene extract was tested for antioxidant activity. The optimal conditions for β-carotene extraction were found to be extraction at 51 ℃ and 34 MPa for 80 min. Under these conditions, the extraction yield of β-carotene was 8.79 mg/100 g. The resulting extract had stronger scavenging activity against ABTS free radials than Trolox and β-carotene standard. Moreover, its total reducing power and DPPH radical scavenging activity were higher than those of β-carotene standard but weaker than those of Trolox.

n this study, an orthogonal array design was applied to optimize conditions for the hydrolysis of Flos Lonicerae by cellulase for polysaccharide extraction. The effects of enzyme concentration, temperature, pH and hydrolysis time on polysaccharide yield were explored. The optimum hydrolysis conditions for a considerably enhanced extraction yield of polysaccharide were determined as follows: 1.5% of enzyme concentration, 50 ℃, pH 5.0 and 50 min of extraction time.

This study was undertaken to optimize condition for the extraction of total flavonoids from Xinjiang Ruoqiang jujubes. One-factor-at-a-time method was used to investigate the effects of ethanol concentration, temperature, extraction time and solid-to-solvent ratio on the extraction yield of total flavonoids. Maximum extraction yield of total flavonoids was reached after 90 min of extraction. Using a three-variable, three-level Box-Behnken experimental design coupled with response surface methodology, ethanol concentration, temperature and solid-to-solvent ratio were optimized to be 45%, 90 ℃ and 1:35 (g/mL), respectively. Under the optimized conditions, the actual extraction yield of total flavonoids was 14.34 mg kaempferol equivalent/g, which was 97.9% as compared to the predicted value (14.647 mg kaempferol equivalent/g). The obtained extract had an ethyl acetate fraction that revealed potent antioxidant activity and was comparable to BHT.

Response surface methodology was employed to optimize the aqueous enzymatic extraction of oil and protein from perilla seeds. The extraction yields of protein and oil were investigated as a function of six extraction conditions including enzyme type, solid-to-solvent ratio, pH, temperature, enzyme loading and hydrolysis time. As a result, a mathematic model was established using a Box-Behnken experimental design. The model was statistically significant and allowed accurate prediction of extraction yields of protein and oil under various conditions. Alcalase was identified as the best enzyme for the aqueous enzymatic extraction of oil and protein from perilla seeds and the optimized values of solid-to-solvent ratio, pH, temperature, enzyme loading, and hydrolysis time for extracting oil and protein from perilla seeds were 1:4, 8.94, 61.3 ℃, 1.5% and 4.47 h, respectively. Under the optimized conditions, the extraction yields of oil and protein were e 85.59% and 73.43%, respectively.

In this study, fresh okara was dried and subjected to ultrafine comminution alone or screw extrusion followed by ultrafine comminution. We established the optimum conditions for drying fresh okara and explored the effects of ultrafine comminution alone and in conjunction with screw extrusion on the particle size distribution and processing properties of okara powder. Ultrafine okara powder had better particle size distribution and processing properties than ordinary okara powder. The average particle sizes (D50) of ultrafine powder samples obtained after comminution for 10, 20, 30, 60 min were less than 10 μm and the 20-min ultrafine powder sample showed the best dispersibility, a water solubility of 21.34% and enhanced water-holding capacity and expansibility and yielded 4.5 g of filtration residue, suggesting that the optimum comminution time was 20 min. The combined use of screw extrusion and ultrafine comminution, although causing the color of okara to darken, could notably increase the dispersibility of okara powder in comparison with ultrafine comminution alone, and only 1.53 g of filtration residue was obtained from the resulting power, thereby being more suitable for the production of instant food products.

Protein isolates were prepared from cold-pressed pumpkin seed cakes using alkaline solubilization and acid precipitation. Response surface methodology was used to optimize extraction conditions to obtain maximum extraction efficiency. The optimum conditions for protein extraction were found to be extraction at 50 ℃ for 22.5 min with a solid-to-solvent ratio of 1:12 (g/mL). Under these conditions, the average recovery of total solids was 23.92% and the protein isolates contained 86.48% protein (wet basis; 9.31% water content). Analysis of physiochemical and functional properties showed that the crude protein extract had excellent processing properties. Especially, it was found that its water-holding and oil-binding capacities were higher than those of soybean protein isolate and varied very significantly with concentration and heating time. The emulsifying capacity of the crude protein extract increased with increasing concentration, whereas its emulsion stability dramatically decreased at a concentration of 5%. The two parameters indicated highly significant variations with protein concentration and exhibited a general upward trend with increasing protein concentration. This extract revealed an increasing trend in foaming capacity but almost no changes in foam stability with increasing concentration.

Response surface methodology was used to optimize conditions for the enzymatic hydrolysis of buckwheat protein with alkaline protease to maximize the degree of hydrolysis (DH). The maximum DH value was obtained under the optimized hydrolysis conditions: a hydrolysis temperature of 64 ℃, pH9, an enzyme loading of 3704 U/g and a substrate concentration of 7.8 g/L. The predicted and observed DH values were 37.43% and 37.35%, respectively, suggesting good agreement.

This study aimed at determining the optimum hydrolysis conditions for the extraction of flavonoids from lotus leaves. Cellulase and pectinase were used in combination for one-step hydrolysis of lotus leaves and the solvent used was 70%. The effects of five extraction conditions including solid-to-solvent ratio, pH, enzyme dosage, temperature and hydrolysis time on extraction efficiency were investigated by one-factor-at-a-time method. The optimum solid-to-solvent ratio was found to be 1:20 g/mL. pH, enzyme dosage, temperature and hydrolysis time were optimized using a 16-run orthogonal array design to be 3.5, 3.0 h, 35 ℃, 2800 U/g cellulase + 2000 U/g pectinase, respectively. Under the optimized conditions, the extraction yield of flavonoids was 3.74% compared with 1.59% for aqueous extraction technique as optimized also using a 16-run orthogonal array design (P＜0.01). Hence, we concluded that enzymatic hydrolysis provides a high-yield method for the extraction of flavonoids from lotus leaves.

The pepsin-catalyzed hydrolysis of grass carp bladders was optimized by response surface methodology to improve the extraction yield of collagen. We explored the effects of hydrolysis parameters, enzyme loading, hydrolysis time and liquid-to-solid ratio on the extraction yield of collagen. Their optimal values for collagen extraction were found to be 40 mg/g, 48 h and 80:1 (mL/g), respectively. Under the optimized conditions, the actual extraction yield of collagen was 17.82%, which was close to the predicted value (18.04%). The results of analysis of variance showed that the fitted regression model was reliable, and each hydrolysis parameters had a significant effect on the extraction yield of collagen.

This study was carried out to optimize the extraction of lycopene from cherry tomatoes. Cherry tomatoes were pretreated before extraction. Soaking in the same volume of absolute ethanol for 2 h and centrifugation for water removal was found optimum for the pretreatment of cherry tomatoes. A mixture of acetone and n-hexane was found to be the solvent for lycopene extraction. The optimal conditions for lycopene extraction using the mixture were determined using an orthogonal array design to be extraction at 40 ℃ for 2.5 h with a solvent-to-solid ratio of 3:1 (mL/g). Under these conditions, the extraction yield of lycopene was 4.08 mg/ 100 g.

A new method for the analysis of volatile components from rapeseeds and peanuts was established using improved solvent-free microwave extraction (ISFME)-comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC/TOF-MS). Carbonyl iron powder was used for the solvent-free extraction of volatile oil from rapeseeds and peanuts and its optimized ratio to crop seeds was 1:5 (m/m). A GC×GC/TOF-MS system equipped with DB-5MS and DB-17 columns was used and the modulation period and initial temperature were set as 4 s and 35 ℃, respectively. Compared with the conventional solvent-free microwave extraction (CSFME) method, the improved CSFME (ICSFME) method was time saving, and only 20 min was required for oil extraction from rapeseed and peanut compared with 50 min for the CSFME method. Moreover, the improved CSFME required less energy consumption. The volatile oil extracted by both methods had the same chemical composition as determined by GC×GC/TOF-MS. Many heterocyclic compounds as well as oxidized volatiles (alcohol, aldehydes, ketone, acid, ester and hydrocarbon) and sulfur-containing, nitrogen-containing and benzene ring-containing compounds were identified and heterocyclic compounds were predominant among these compounds. The volatile oil obtained by the ICSFME method showed a higher relative content of oxidized volatiles, which contributed to the formation of more flavor-active substances.

Headspace solid phase micro-extraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to determine the effect of different drying methods (sun, hot air, microwave, vacuum and vacuum freeze) on the aromatic composition of okara, and the odor thresholds and relative odor activity values (ROAV) were measured to identify major beany flavor compounds in okara. A total of 52 volatile compounds were detected in okara samples dried by five different methods, mainly aldehydes, ketones, esters, alcohols, etc. The predominant aromatic compounds in sun dried okara were 3-hydroxy-2-butanone (18.29%), hexanal (16.30%) and acetone (11.87%) and the most beany flavor compounds with the highest relative content were found in sun dried okara followed by vacuum dried okara. Volatile compounds showed a lower relative content in hot air dried okara, whereas the relative contents of alcohols and ketones were higher in microwave dried okara. Benzaldehyde (11.18%) and 2,3-butanedione (11.27%) were found in vacuum dried okara as dominant aromatic components. The major volatile compounds in vacuum freeze dried okara were ethyl acetate (46.72%) and acetone (22.86%) and the beany flavor compounds accounted for only 1.81%.

A direct competitive chemiluminescene enzyme immunoassay (dcCL-EIA) was developed for the rapid determination of fumonisin B1 in cereal samples. Assay parameters including coating antigen (FB1-OVA) and enzyme labeled anti-FB1 antibodies and reaction time were optimized to be 0.4 μg/mL, 3000-fold dilution and 20 min, respectively. The analytical sensitivity of the developed method was 0.13 ng/mL, and the IC50, intra-assay and inter-assay coefficients of variation were 1.43 ng/mL, 2.4% and 9.2%, respectively. The recovery rates for FB1 in negative corn samples at three levels were in the range of 100.2%～115.4%. A total of 40 cereal samples were screened by DC-CLEIA, ELISA kit and HPLC, respectively. The results indicated that the correlation coefficients (R2) for the results from ELISA kit and HPLC were 0.9793 and 0.9851, respectively. The dcCL-EIA method is sensitive, rapid and accurate, and is suitable for the large-scale screening of FB1 in cereal samples.

A sensitive spectrophotometric method has been developed for the determination of trace amounts of benzoyl peroxide (BPO) based on the oxidation of I- to I3- by BPO and the further reaction of I3- with rhodamine 6G to form an ion association complex in H2SO4 solution. The ion association complex had maximum absorption at 560 nm and its absorbance (A) showed a good linear relationship with BPO concentration (c, mg/mL) within the range of 0.3–5.9 mg/L: A = 0.2174 + 0.0833 c, with a correlation coefficient of 0.9985. The calculated apparent molar absorption coefficient was 2.13 × 104 L/(cm·mol). The average spike recovery rates of BPO in two commercial samples were 96.5% and 98.6%, respectively. Satisfying results were obtained in practical applications of this method with a relative error of less than 5% compared with HPLC results.

The fermentation of Spirulina by Mucor wutungkiao was carried out as described for sufu. Direct thermal desorption (DTD)-GC-MS was used to determine volatile compounds in non-fermented and fermented Spirulina. The flavor of Spirulina was substantially improved by Mucor wutungkiao fermentation and changes in the kinds and amounts of volatile compounds were observed. Moreover, the kinds of alcohols and some unpleasant flavor compounds including aldehydes and ketones obviously decreased and new compounds responsible for braised meat and milky flavors were formed, 2-hydroxy-cyclopentadecanone and 5,6,7,7-tetrahydro-4,4,7a-trimethyl-(R)-2(4H)-benzo-furanone.

An HPLC-DAD-atmospheric pressure chemical ionization (APCI)-MS method was proposed to quantify and qualify lutein stereoisomers. A C30 column was found to be more effective in separating lutein stereoisomers than a C18 column. The mobile phase was composed of methanol and deionized water (98:2, V/V). A good relationship between peak area and injection amount was found in the range of 40 to 200 ng. The proposed method was accurate, reproducible, economical and suitable for the determination of lutein stereoisomers.

The tocopherol and phytosterol composition of 45 peanut cultivars from Shandong, Guangdong and Henan provinces was comparatively analyzed by HPLC. The results showed that three VE isomers (α-, γ-, and δ-VE) and three sterols (campsterol, stigmasterol and β-sitosterol) were found in each peanut cultivar. Three provinces were Henan, Guangdong and Shandong in the decreasing order of total VE content, Guangdong, Henan and Shandong in the decreasing order of α-VE content, Henan, Shandong and Guangdong in the decreasing order of γ- and δ-VE contents, and Henan, Shandong and Guangdong in the decreasing order of total sterol, campstreol, stigmasterol, and β-sitosterol contents. For each peanut cultivar, α-VE was the most predominant VE isomer, accounting for 70.37%–78.27% of the total VE amount, and β-sitosterol was most dominant among three sterols, representing 61.98%–71.65% of the total sterol amount.

A rapid HPLC method was developed for the determination of angiotensin Ⅰ-converting enzyme (ACE) inhibitory activity. Hippuric acid was separated on an ODS C18 column (150 mm × 4.6 mm, 5 μm) using a mobile phase consisting of acetonitrile and water (20:80, V/V, containing 0.5‰ methanoic acid) at a flow rate of 1 mL/min and detected at 228 nm. A good linear relationship was observed for hippuric acid over the concentration range of 0.1 to 500 μg/mL with a correlation coefficient of 0.9999. The average spike recovery rates of hippuric acid were 89.77%–99.57% with a relative standard deviation (RSD) of 0.01%–1.52% (n = 3). The HPLC method was simple, rapid, reproducible, accurate and suitable for the analysis of ACE inhibitory activity in vitro as demonstrated by its applications to determine different ACE inhibitors.

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis and chip bio-analysis system were used to identify five puffer species. A 464-bp fragment of mitochondrial cytochrome b gene was amplified by PCR and the products were digested with the restriction endonuclease DdeⅠ, Hae Ⅲ and Nla Ⅲ, respectively. The resulting fragments were further resolved on DNA chip. Five puffer species were successfully identified by this method. In conclusion, PCR-RFLP and chip bio-analysis system could provide a fast, easy, automatic and reliable analysis approach.

A high performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of four major anthocyanins in Zijuan tea, pelargonidin-3,5-diglucoside, cyanidin-3-O-galactoside, pelargonidin and malvidin. The chromatographic separation was achieved on a YMC-Pack ODS-AQ C18 column using a mobile phase made up of 0.5% formic acid and acetonitrile at a flow rate of 0.8 mL/min by gradient elution Column temperature and detection wavelength were set as 35℃ and 520 nm, respectively. The anthocyanins were separated well and showed good linear relationship over the concentration range of 0.03–0.10 mg/mL with correlation coefficients greater than 0.999. The precision RSDs of the HPLC method were 0.73%–1.48% (n = 5), and the recovery rates of these anthocyanins were in the range of 94.84%–96.46%. The contents of pelargonidin-3,5-diglucoside, cyanidin-3-O-galactoside, pelargonidin and malvidin in Zijuan tea were determined to be 83.5, 227.0, 46.3 μg/g and 70.5 μg/g, respectively. This method was convenient, rapid, accurate and applicable to determine anthocyanins in Zijuan tea and other tea samples.

High performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS) with accelerated solvent extraction (ASE) was used to establish a method for quantitative detection of perfluorooctanoic acid (PFOA) in paper food containers. Samples were extracted by ASE method with methanol. The resulting extract was cleaned up using a C18 solid phase extraction (SPE) column, and separate on a chromatographic C18 column using methanol and deionized water as mobile phases by gradient elution. Instrumental analysis was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in the multiple-reaction monitoring (MRM) mode. The developed calibration curve was linear in the range of 0.5–50 ng/mL with a correlation coefficient (r2) of 0.9993. The recovery rates for PFOA were in the range of 90.2%–103.3% with relative standard deviations of 2.74%–6.03%. The detection limit (RSN = 3) was 0.1 µg/kg. This method was easy, time-saving, sensitive and suitable for the determination the PFOA in paper foods containers.

Twenty-six samples of fresh and processed aquatic products from different species were determined for boron content by inductively coupled plasma mass spectrometry. Boron content in Antarctic krill, Ark shell, oyster and Ruditapes philippinarum (1.183–4.240 mg/kg) were much higher than other samples, while turbot had the lowest boron content (0.006 mg/kg). In decreasing order of boron content, different living environments were wild marine, farmed freshwater and farmed marine for fish, wild marine, farmed marine and farmed freshwater for shrimp, and farmed marine and farmed freshwater for crab. Boron content in aquatic products ranged from 0.458 to 0.849 mg/kg, lower than 0.900 mg/kg. We assessed most of the tested fresh and processed aquatic products to be safe to eat. However, Antarctic krill, oyster, Ark shell and Ruditapes philippinarum should be eaten less for safety purpose due to higher boron content.

A gas chromatography (GC) method was established for determining trifluralin residues in aquatic products in this study. The sample preparation procedure involved homogenization, acetone extraction, n-hexane partition (liquid-liquid extraction) and cleanup on a Florisil solid-phase extraction column before GC analysis. The quantification was performed by external standard method. The GC method showed good linear relationship over the concentration range of 0.5–100 ng/mL. The limit of quantification was 1.0 ng/g. The recovery rates of trifluralin from eel, crab, clams, crucian and shrimp when spiked at 1.0, 2.0 ng/g and 10.0 ng/g were 74.8%–99.7%, respectively. This method was simple, sensitive and accurate, and therefore could meet the requirements for the determination of trifluralin residues in aquatic products.

In this work, a method to detect live E. coli O157:H7 was established using propidium monoazide (PMA) coupled with quantitative polymerase chain reaction (qPCR). The minimum inhibitory concentration against DNA amplification from dead bacteria was 10 µg/mL, and PMA did not inhibit DNA application from live bacteria at concentrations equal to or lower than 20 µg/mL. Covalent cross-linking of PMA with DNA was induced by strong light illumination for 5 min and meanwhile, free PMA was completely inactivated, resulting in the avoidance of false negative results. When the live to dead bacteria ratio was more than 1%, PMA pretreatment allowed the elimination of DNA interference from thermally inactivated bacteria and therefore live bacteria could be quantified.

Fatty acids, amino acids, and aromatic compounds from fruit bodies and cultured mycelia of Tricholoma matsutake were analyzed by gas chromatography-mass spectrometry (GC-MS). Both materials contained common fatty acids such as palmitic acid, stearic acid, linoleic acid and oleic acid and had the same amino acid composition, but the contents of Asp, Glu, Gly, Ala and Lys of the cultured mycelia were higher than those of the fruit bodies. The unique aroma components in T. matsutake were phenylacetaldehyde, benzaldehyde, 2-decenal and C8 compounds, and could provide critical references for quality evaluation criteria of Tricholoma matsutake. Collectively, the above results suggest that cultured mycelia of Tricholoma matsutake are a new T. matsutake resource that has a great potential for industrial development and utilization.

A total of 74 volatile compounds were extracted and separated from 8 Anxi Tieguanyin tea samples (harvested at four different seasons; two degrees each season). The major aromatic compounds in Anxi Tieguanyin tea were nerolidol, farnesene, indole, phenylethyl alcohol, (E)-2-hexenal, nonanal, benzeneacetaldehyde, methyl linoleate, methyl linolenate, methyl palmitate, (Z)-3-hexenyl hexanoate, 3-hexen-1-ol benzoate, octanoic acid, 2-phenylethyl ester, delta- nonalactone, cis-jasmone, farnesylacetone, palmitic acid, and geranyl linalool isomer as demonstrated by principal component analysis (PCA). A PCA model for the aroma quality evaluation of Anxi Tieguanyin tea was constructed using the variance contribution rates of various eigenvalues βi (i = 1, 2, ……, k) as weight coefficients based on the comprehensive evaluation function: F = β1F1 + β2F2 +…+ βkFk and used to calculate aroma quality score for each tea sample for aroma quality evaluation. The evaluation results were in good agreement with those obtained from sensory evaluations, indicating the developed method to be feasible.

A new method was established to determine tryptophan and tyrosine in four edible plants wildly grown in Zhengzhou region, Sonchus asper, Plantago asiatica, Vigna minima and Pyracantha fortuneana. Samples were hydrolyzed with with 6 mol/L sodium hydroxide solution determined by molecular fluorescence spectrometry. The average contents of tryptophan and tyrosine in the wild plants were 1.37–2.63 mg/g and 7.98–25.83 mg/g, respectively, with a relative standard deviation equal to or less than 5.4% (n = 5). The proposed tryptophan standard curve showed good linear relationship over the concentration range of 0.00–0.10 μg/mL. The method exhibited a limit of detection of 0.011 μg/mL and 0.033 μg/mL and a limit of quantification of 0.037 μg/mL and 0.11 μg/mL for tryptophan and tyrosine, respectively. The propose tyrosine standard curve displayed a linear range of 0.0–1.0 μg/mL. The average spike recovery rates of tryptophan and tyrosine in these four plants were 93.5%–105% and 94.6%–100.5%, respectively. This method was simple, sensitive, rapid, and suitable for practical applications.

The major nutrients, amino acid composition and mineral element contents of blackberry leaves were analyzed and compared with those of the leaves of other plants such as wolfberry, persimmon, mulberry, Ampelopsis grossedentata and Vaccinium dunalianum. Blackberry leaves were found to have higher contents of crude protein (20.39 g/100 g), cellulose (14.52 g/100 g) and total flavonoids (3.75 g/100 g). It contained a full range of amino acids and were higher in the contents of total amino acid and essential amino acids than the leaves of other five plants. Moreover, micro-mineral elements essential for human body such as Ca, K, Mg, Na, P, Fe, Zn, Cu, Mn showed higher levels in blackberry leaves, small amounts of Cd, Cr, and Co were also found, and the Pb content was 3.18 mg/kg, which was lower than the national limit for tea. This study demonstrates that blackberry leaves can be processed into high-quality tea and hold promise for further research and development due to abundance of flavonoids.

A new resonance light scattering (RLS) method for the rapid determination of residual chlorpyrifos in vegetables such as Chinese leek, amaranth, sweet potato, and black cabbage was developed based on the reaction of chlorpyrifos with crystal violet-potassium iodide in Britton-Robinson butter at pH 11.00 to generate an ion association complex. Chlorpyrifos had maximum resonance light scattering peak at 650 nm. A good liner relationship (r = 0.9981) was observed between chlorpyrifos concentration over the range of 0.016–0.877 μg/mL and relative scattered light intensity. The detection limit of chlorpyrifos was 0.016 μg/mL and the relative standard deviations (RSDs) of precision for 5 replicate determinations were less than 2.5%. The average recovery rates of chlorpyrifos in four vegetables were 91.4%–100.3% (n = 5). This method was simple, rapid and sensitive and satisfying results were obtained in its practical applications.

An efficient and sensitive method was established to detect Cordyceps sinensis (Berk.) Saccardo using real-time PCR. The internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) in Cordyceps sinensis (Berk.) Saccardo. was used as a target molecular marker and sequence homology analysis was carried out on various Cordyceps species. A set of specific primer and probe for real-time PCR was designed which allowed the amplification of 80-bp DNA fragments. The detectable DNA template concentration of the real-time PCR method for Cordyceps sinensis (Berk.) Saccardo was as low as 0.0001 ng/μL.

A new method for the rapid determination of danofloxacin mesylate was proposed based on the fact that the chemiluminescence (CL) reaction between luminol and potassium periodate is sensitized by danofloxacin mesylate in alkaline solution. Samples were extracted with phosphate buffer solution and the extract was cleaned up using a solid-phase extraction column and determined by flow-injection chemiluminescence as described for the standard curve preparation. Under optimal conditions, an excellent linear relationship between chemiluminescence intensity and danofloxacin mesylate concentration was in the range of 4.53 × 10-6–2.27 × 10-3 mg/mL. The limit of detection for danofloxacin mesylate was 3.76 × 10-6 mg/mL with a relative standard deviation (RSD) of 1.9% (n = 11). The average recovery rates of danofloxacin mesylate when spiked to pork and chicken liver were in the range of 69.00%–97.50% (n = 5). 

The edible parts of 9 marine snails from Lianyungang sea area were analyzed for the contents of trace elements and the safety of heavy metal contents was evaluated. Different marine snails and different tissues of the same species showed variations in the contents of Pb, Cd, Sn, As, Mn, Fe, Ni, Ag, Se, Cr, Co, Zn and Cu. Essential trace elements for humans such as  Fe, Cu, Zn, Co, Mn, Cr, Se and Sn were found in all the tested snails, but the heavy metals As, Cd and Pb revealed a high residual index (I) and showed variations among different marine snails and among different tissues. All the snails had As contents exceeding the national food hygiene standard. As and Cd revealed the highest content in the foot muscle and visceral mass of Hemifusus tuba, respectively. Although Pb contents exceeding the national food hygiene standard were found in two samples of Umbonium thomasi (I = 6.5 and 5.5, respectively), the foot muscle of Glossaulax didyma (I = 2.1) and the visceral mass of H. tuba (I = 1.22), the foot muscle and visceral mass of other snails had safe Pb contents and I values smaller than 1. In addition, the foot muscle of H. tuba had a Cr I value of 1.21, while the Cr I values of the visceral mass of Glossaulax didyma and both tissues of eight other sails were less than 1.

A high performance liquid chromatographic (HPLC) method was developed for determining bisphenol A (BPA) residue and migration in polycarbonate (PC) baby milk bottles. Solid-phase extraction (SPE) for analyte enrichment was used to study the effect of soaking time on BPA migration from PC baby bottles. BPA residues were detected in a certain brand of baby bottle at a level of 10.7 mg/kg. The migration of residual BPA from PC baby bottles to water reached the maximum level after exposure for 1–6 h, showed no obvious changes with increasing exposure time and basically reached equilibrium after 10 h exposure. During the whole process, the specific migration amount of BPA was 0.36 mg/kg, and the final concentration in water was 0.025 mg/L. The limit of detection of the HPLC method was 0.6 ng/mL (RSN = 3). The average recovery rates of BPA across three spike levels were 85.9%–89.5% with a relative standard deviation (RSD) of 0.78%–1.43% (n = 4).

Head space-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the composition and contents of major volatile compounds in Magnum hops. The identification and validation of volatile compounds were performed using mass spectral library searching based on Kovats retention index (KI). Greatly different results were obtained for the volatile composition of Magnum hops using HS-SPME and the conventional steam distillation (SD) method. A total of 73 volatile compounds were detected in Magnum hops by HS-SPME, together accounting for 99.35% of the total pear area, and terpenes, mainly humulene and β-caryophyllen, together accounted for 85.35% of the total amount of volatile compounds compared with only 0.24% for their oxidized products. A total of 63 identified volatile compounds were extracted by the conventional SD method, together accounting for 98.42% of the total peak area, and terpenes accounted for only 68.41% of the total amount of volatile compounds while the content of oxidized terpenes was as high as 13.27%. For other oxygen-containing compounds such as alcohols, esters and ketones, similar results were obtained using both extraction methods, showing relative contents of 2.65%, 8.14% and 1.29% in the HS-SPME sample and 3.42%, 10.55% and 2.51% in the SD sample. Moreover, three aldehydes, together accounting for 0.99% of the total amount of volatile compounds, were detected in the HS-SPME sample rather than the SD sample. The above results suggest that the major volatile compounds in Magnum hops are humulene, β-mycrene, β-caryophyllene, humulene oxide, caryophyllene oxide, δ-cadinene, muurolene, 4-decenoic acid, methyl ester, copaene, 2-propanone, γ-cadinene, α-selinene, β-selinene, β-pinene, linalool, (E)-β-farnesene and geranyl formate.

An analytical method for the determination of moxicillin (AMO) residues in eggs was established using HPLC with fluorescence detection. AMO residues in egg samples were extracted with acetonitrile, and the acetonitrile extract was further extracted with saturated methylene chloride and derivatized with salicylaldehyde under acidic conditions in boiling water. The mobile phase used for the chromatographic separation of the derivative was composed of 0.01 mol/L potassium dihydrogen phosphate (A) and acetonitrile (B) at a flow rate of 1.0 mL/min. Fluorescence detection was completed at excitation and emission wavelengths of 354 nm and 445 nm, respectively. The HPLC method showed good linear relationship over the concentration range of 5.0–800 ng/mL (r = 0.9991). The average recoveries of AMO at spike concentrations between 5 ng/g and 125 ng/g were 80.47%–89.53% with a relative standard deviation (RSD) of 5.77%–6.87% and the intra-day and inter-day RSDs were 8.61%–9.61% and 11.01%–14.80%, respectively. The limit of detection and limit of quantification for AMO were 1.2 ng/g (RSN = 3) and 3.9 ng/g (RSN = 10), respectively (n = 6). This method was simple, fast, sensitive and suitable for the determination of AMO in eggs.

The distribution of major chemical components during the production of steamed and roasted whole tartary buckwheat tea samples was tracked to explore the effects of steaming, roasting and reconstructed granulation on the aroma and nutritional components of tartary buckwheat tea. Meanwhile, both tartary buckwheat teas were comparatively analyzed for volatile aroma components by solid-phase microwaveextraction (SPME) coupled with GC-MS. The final products obtained following different procedures showed significant differences in chemical composition (P＜0.05). During the production of steamed tartary buckwheat tea, proteins were mainly distributed in the yellow powder at a level of 27.51%, the reducing sugar content of 0.69% in the raw material decreased to 0.28% in the fine product, and total flavonoids were mainly distributed in the polished powder and yellow powder at levels of 4.98% and 4.63%, respectively. As a result, the total flavonoid content of the final product was as low as 1.38% compared with only 1.20% for roasted tartary buckwheat grains. The total flavonoid content of tea-containing reconstructed granules prepared from buckwheat husk powder, rich in flavonoids (4.56%), was as high as 6.87%. Roasted whole tartary buckwheat tea as a mixture of roasted tartary buckwheat grains and tea-containing reconstructed granules had considerably better quality and flavor than its steamed counterpart. The major aroma compounds of steamed tartary buckwheat tea were alkanes and alkenes, while roasted tartary buckwheat tea contained aldehydes and alkanes as major aroma compounds and was also rich in phenols, alcohols, ethers, ketones and esters, which caused better flavor in roast tartary buckwheat tea and than steamed one.

Volatile compounds in samples collected at different stages during the post-fermentation of Aspergillus-type douchi were analyzed by solid phase microextraction (SPME) combined with GC-MS and quantified by area normalization method. The major volatile flavor compounds during the whole post-fermentation process included 5 alcohols, 7 esters, 3 aldehydes, 1 acid, 1 ketone, 1 pyrazine and 2 alkanes as demonstrated by PCA (principal component analysis) analysis of their relative contents. More volatile compounds were detected as the post-fermentation proceeded. 1-octen-3-ol, 3-methyl-1-butanol, 2-methyl-butanoic acid, ethyl ester, hexanoic acid, ethyl ester, benzeneacetaldehyde, 3-ethoxy-1-propene, 4-hydroxy-2-butanone, tetramethyl pyrazine, 2-methyl-propanoic acid and ethyl ester were predominant during the entire post-fermentation process, and 3-methyl-1-butanol, 2-methyl-propanoic acid, ethyl ester, hexanoic acid, tetramethyl pyrazine, and 2-methyl-propanoic acid and ethyl ester had major contributions to the formation of flavor in Douchi and their contents increased with prolonged post-fermentation time. PCA analysis suggested that the best flavor was achieved after 15 d of post-fermentation followed by 25 d and 30 d.

An effective method was developed for speciation analysis of calcium in milk by flame atomic absorption spectrophotometry. The effects of ethanol concentration, centrifuge temperature, centrifugal force and centrifugation time on protein sedimentation were discussed. The best conditions for separating calcium from samples were found to be protein sedimentation with 50% and centrifugation at 2 ℃ and 6000 × g for 6 min. The best La(NO3)3 concentration for releasing bound calcium was 6.00 mg/mL as determined by analyzing the effect on absorbance. Under the optimized conditions, the total calcium concentration of milk was determined to be 808.6 μg/mL and the bound and free calcium concentrations were 641.8 μg/mL and 173.0 μg/mL, which accounted for 79.4% and 21.4% of the total calcium, respectively. The precision (RSD) of the developed method was less than 3.3%, and the limit of detection was 0.11 μg/mL. The average spike recoveries of calcium was  97.0% with a RSD of 1.7%. This method was accurate, stable and applicable.

A method to determine 17α-methyltestosterone (MET) residues in aquatic products was developed using LC-C18 solid phase extraction (SPE) combined with HPLC. Samples were extracted with diethyl ether under ultrasonic assistance. After concentration by rotary evaporation, the extract was defatted with n-hexane, cleaned up using an LC-C18 column, blown to dryness and dissolved again before reversed-phase HPLC analysis using a mobile phased made up of methanol and 0.1% formic acid (1:1, V/V). The average recovery rates of the HPLC method for MET at spike concentrations of 7.0–200 μg/kg were in the range of 82.0%–86.0% with a relative standard deviation (RSD) less than 7%. The limit of quantification (LOQ) for MET was 7.0 μg/kg.

Objective: The fatty acids were extracted from Annona seeds and analyzed by gas chromatography - mass spectrometry (GC-MS). Methods: Annona seeds oil was extracted from by Soxhlet and the methyl ester product was analyzed by GC-MS technology. Results: the yield of Annona seeds oil was (24.17±1.08)%. The Annona seeds oil contains 16 types of fatty acids and the main fatty acids include oleic acid (42.91%), linoleic acid (38.53%), 2, 6, 10, 14 - tetramethyl pentadecanoic acid (15.43%), octadecadienoic acid (1.33%), arachidonic acid (1.27%) and heptadecanoic acid (0.52%). Unsaturated fatty acid content was up to 82.77%. Peroxide value of 1.32 was lower than that of the edible vegetable oil provided by food safety standards. Conclusion: High nutritional value of Annona seeds oil can be ascribed to rich content of unsaturated fatty acids and low peroxide value.

The volatile compounds from fresh and dried Allium cepa L. were extracted by solid phase micro-extraction and the volatile composition profiling were analyzed by GC-MS combined with computer-assisted library search. Results showed that a total of 49 types of volatile compounds were identified from the fresh and dried Allium cepa L. 30, 28, 28, 25 types of volatile compounds were identified from 4 samples, which accounted for 94.25%, 96.01%, 83.40% and 86.11% of the total peak areas in four samples. These compounds were mainly sulfur compounds, alcohols, aldehyde, ester and other chemical groups. There was significant difference in volatile compound pattern and their relative contents from fresh and dried Allium cepa L.

Enterocin LM-2, a broad-spectrum bacteriocin isolated from Chinese traditional cheese, was produced by Enterococcus faecium LM-2. In order to examine the potential of enterocin LM-2 as a biopreservative in sliced cooked ham, the effect of enterocin LM-2 at different concentrations (80, 320, 1280 AU/g) on microbiological, physicochemical and sensory quality properties of sliced cooked ham during the refrigerated storage at 4 ℃ was explored in this paper. The addition of enterocin LM-2 could substantially suppress the growth of microflora, especially Listeria monocytogenes and Salmonella enteritidis, and decrease the accumulation of TVB-N and lipid oxidation during refrigerated storage of sliced cooked ham. Overall, the most effective treatment was achieved by adding 1280 AU/g enterocin LM-2, which could extend the shelf life up to 49 days and produce a better sensory profile during the whole storage period. These results clearly indicate that enterocin LM-2 has a great potential as a biopreservative for enhancing the safety and quality of refrigerated sliced cooked ham.

The effect of the treatment with 1-MCP and ClO2 on postharvest quality and physiology of red globe grape during freezing-point storage was explored through determining the physiological and biochemical indexes. The results showed that the treatment of 1-MCP coupled with ClO2 revealed more advantages to 1-MCP and ClO2 treatments, and reduced the loss of grape due to rot during the storage. In addition, the treatment of 1-MCP coupled with ClO2 could maintain titratable acidity, total soluble solids, VC content, grape quality and nutrients, inhibit respiratory intensity and ethylene production, slow down the growth of cell membrane permeability, decrease MDA content, increase the activity of POD and SOD, and delay the aging process.

An accelerated shelf life testing (ASLT) model was applied to determined shelf-life of not-from-concentrated Jincheng orange juice which was freshly squeezed in laboratory. Selected temperature were chosen as accelerated factor and the sensory evaluation and physical and chemical indicators were checked at regular intervals. The shelf life storage test was performed o 35 d and 12 d at 30 ℃ and 40 ℃, respectively. The results show that with the increase of storage time, the ascorbic acid content of not-from concentrated Jincheng orange juice significantly decreased while the total color difference and browning index increased sharply at 30 ℃and 40 ℃. These three indices were significantly correlated to overall sensory assessment (r＞0.95). It’s reasonable to choose deterioration of ascorbic acid, total color difference and browning index as the key deteriorated indicators for not-from-concentrated Jincheng orange juice during the storage.

Effect of heat treatment and pretreatment (prior to heat treatment) with dimethylthiourea (DMTU, a trap for H2O2) on cell membrane injury and metabolism of reactive oxygen species in cucumbers stored at 2 ℃was investigated. The content of malondialdehyde (MDA), the chilling injury index and electrolyte leakage in control cucumbers were increased during the cold storage; H2O2 content, the activities of superoxide dismutase (SOD) and catalase (CAT) exhibited an initial fast increase followed by a reduction; the activities of peroxidase (POD) and ascorbate peroxidase (APX) were decreased with storage time. Heat treatment alleviated the chilling injury development, enhanced the endogenous H2O2 content during early storage, postponed the increase of MDA content and increased the activities of CAT, APX and SOD in cucumbers stored at low temperature. However, heat treatment had no significant effect on POD activity, suggesting that the enzyme did not play a key role in chilling tolerance in relation to antioxidant activity. On the contrary, DMTU treatment counteracted heat treatment-induced tolerance in cucumbers, exhibiting higher chilling injury index and MDA content, and decreased activities of CAT and APX. It is suggested that H2O2 mediated chilling resistance induced by heat treatment in cucumbers. 

After receiving dipping treatment with composite chitosan/nano-SiOx solution (CTSS) for 30, Yanhong peach fruits were stored under the conditions of 26-29 ℃ and relative humidity of 65%-75%. The dehydration rate of the fruits were optimized with U10(102×52) uniform design and L9(34) orthogonal array design. The results indicated that the optimal ingredients in 300 mL solution included chitosan 5.0 g, glycerol monostearate 0.11 g, nano-SiOx 0.07 g, and glycerin 6.0 g. Coating treatment with CTSS revealed the best fresh-keeping effect at the end of the storage period for 20 days. The dehydration rate and the decay index in CTSS group revealed the reduction by 43.96% and 30.56%, while reducing sugar, ascorbic acid and titrable acidity increased by 44.00%, 66.87% and 52.77%, respectively, when compared with those in the control group. These results suggest that CTSS coating can significantly improve the quality of post-harvest fruits and extend the shelf life of Yanhong peach.

This study focused on effects of hydrogen peroxide treatments on postharvest quality of Jiashi muskmelon during cold storage (6 ℃±1 ℃). The results showed that respiratory intensity, ethylene, and firmness were obviously decreased after hydrogen peroxide treatment, meanwhile the lost of moisture content, soluble solid content and vitamin C content were also declined during storage. Bagging after hydrogen peroxide treatment delayed the respiratory peak and reduced the release of ethylene. Those results indicated that hydrogen peroxide treatment could be beneficial to keep good quality of Jiashi muskmelon during cold storage. Comprehensive comparison showed that bagging after 4% hydrogen peroxide treatment was the best storage condition.

Bighead carps treated with ozone water were packaged at the conditions of vacuum (Ⅰ), mixed gas with 30% N2 and 70% CO2 (Ⅱ), mixed gas with 45% N2 and 55% CO2 (Ⅲ), and mixed gas with 60% N2 and 40% CO2 (Ⅳ), respectively, and then stored at freezing-point temperature. The change in freshness of bighead carps during storage was evaluated by determining total bacteria, TVB-N content, TBA value, pH, K value and sensory quality. The results showed that package had a significant impact on freshness of bighead carps during freezing-point storage and the modified atmosphere package was better than vacuum package. The bighead carps packaged with mixed gas containing 30% N2 and 70% CO2 revealed longer shelf life. The quality parameters of bighead carps in the atmosphere package Ⅱ could provide shelf life of 15 days at (－1 ± 0.5) ℃, TVB-N content of 11.37 mg/100 g, and total bacterial number of 1.83 × 105 CFU/g.

The effects of air packaging (AP), vacuum packaging (VP) and modified atmosphere packaging (MAP) on preservation of white shrimp (litopenaeus vannamei) during controlled freezing-point (CF,－2.3-0℃) storage and ice storage were investigated. The influence of different packaging method was assessed on the basis of changes of polyphenol oxidase (PPO) activity, total volatile base nitrogen (TVB-N), total plate count (TPC) and drip loss (DP) combined with sensory evaluation. The results indicated that the PPO activity of white shrimp changed synchronously with its deterioration during storage. Combined use of MAP and CF storage effectively prevented the occurrence of browning in Pacific white shrimps and had an extended shelf life of 10 days compared to AP treated shrimps stored in ice. The white shrimps presented a better color and TPC, TVB-N, TBC and DP were about 5.4 lg((CFU/g)), 25.6 mg/100 g and 3.13%, respectively. However, shrimps treated by AP or CP showed deterioration. Sensory analyses indicated that shrimps treated by VP also had better color compared to AP while but the drip loss was relatively higher, which in turn influenced the sample’s appearance during the late period of storage.

This study is aimed at improving the tenderness and prolonging shelf life of steak by high hydrostatic pressure (HHP) and freezing method. Effect of different treatments on the quality of steak were investigated by analyzing color value, shear force, drip loss, total aerobic count and the storage time. The results showed HPP and freezing pretreatments retained the equivalent tenderness but at a reduced pressure, 100 MPa lower than HPP treatment alone. The percent of drip loss increased initially to the maximum of 3.9% at 400 MPa, and then decreased. However, no significant difference was observed in the color and drip loss of steaks treated by HPP alone. The total aerobic count of freezing + HHP group was significantly lower than the HHP groups. The storage test revealed that the total aerobic count in freezing + HHP steak was 1.9×105 after 16 days of storage at 0–4℃.

Random-Centroid Optimization (RCO) methodology were applied to optimize the extractions of polyphenols and procyanidins from the pulp and seed of Wuweizi (Schisandra chinensis). Six factors, including ethanol concentration, liquid-solid ratio, pH, temperature, heating time and extraction times were investigated. The polyphenol content (pulp) or procyanidin content (seeds), DPPH radical scavenging activity and yield were set as extraction targets. One set of optimum extraction parameters were obtained corresponding to each extraction target. The polyphenol content and yield of the pulp extracts with polyphenol content and yield as investigated targets were much higher than those with the DPPH radical scavenging activity as a target. However, no significant difference was observed on the DPPH radical scavenging activities of the three targets. Among all the seed extracts, those targeting procyanidin content showed a highest procyanidin content while those targeting DPPH scavenging activity or yield also demonstrated the highest extraction target values, respectively. The initial pH value were shown to be the most important factor in pulp polyphenol extraction, while in seed procyanidin extraction, the impact of extraction factors differed with the extraction targets.